<!DOCTYPE html>
<html>
  <head>
    <style>
      legend:first-letter { color: white; background: black; }
      html { font-size: 2em; color: black; background: white; }
    </style>
  </head>
  <body>
    <fieldset>
      <legend>Legend text</legend>
    </fieldset>
  </body>
</html>
